Space telegraphy.



PATENTED OCT. 24, 1905.

3. S. STONE.

PAGE TELBGRAPHY.

APPLICATION FILED JUNE 24, 1905.

TH E E E I STTES P FFICE.

JOHN STONE STONE, OF CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO WILLIAM l/V.SWAN, TRUSTEE, OF BOSTON, MASSACHUSETTS.

SPCIE TELEGIIRAPHY.

Specification of Letters Patent.

Patented Oct. 24;, 1905.

Original application filed May 1, 1905, Serial No. 258,762. Divided andthis application filed June 24 1905. Serial No. 266,857.

Fig. 2 illustrates a means of connecting the Be it known that I, JOHNSToNn STONE, E lower extremity of an elevated conductor to citizen ofthe United States, and a resident of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented a certain new anduseful Improvement in Space Telegraphy, of which the following is aspecification.

This invention relates to the art of transmitting intelligence from onestation to another by means of electro magnetic waves without the use ofwires to guide the waves to their destination and more particularly tomethods whereby the maximum reception of the energy of such waves at thereceiving station may be accomplished.

In my U. S. Letters Patent Nos. 7 67,973 and 767,974, dated Aug. 16,1904, I have disclosed means similar to one of those herein illustrated,and the other means herein illustrated I have disclosed broadly in apaper read by me before the Electrical Section of the Canadian Societyof Civil Engineers at Montreal, Canada. March 9, 1905. and published inthe Electrical Review, New York, March 25, 1905.

The object of my present invention broadly stated is to realize a methodwhereby the re ceiving or translating device of a space telegraphstation may be associated with the receiving oscillator substantially atthe electrical center of such oscillator considered as a whole,

and may be therefore located where the current therein has its maximumamplitude.

For the purposes of this case a space telegraph receiving systemconsidered as a whole may be regarded as consisting of an elevatedconductor per se, or an elevated conductor, connected to the earth or tosome electrical substitute therefor through the means by which thereceiving device is connected therewith. In the present specificationsuch a system considered as a whole will be spoken of as a completeoscillator, and the upper portion thereof as an elevated conductor perm2 or elevated conductor as the case may be. The distinction between theterms employed will be more clearly seen by reference to the detailed.description of the drawings.

In the drawings,

Fig. 1 illustrates a means of connecting the lower extremity of anelevated conductor to the earth and thereby forming a completeoscillator.

a device having for all rates of change a resistance operatorsubstantially equal to that of the elevated conductor, and hence theelectrical substitute of the earth, whereby again a complete oscillatoris formed.

In these figures,

V is an elevated conductor per se.

V and V C L are elevated conductors.

V C L C1 L G E and V C1 L K are complete oscillators.

C C1 C2 C3 are condensers.

L is an inductance coil.

L L; I: and I}; are coils. I1 and I2 are so spatially related that theyform a transformer of great magnetic leakage and similarly 1'2 I3 form asecond transformer of great magnetic leakage, while otherwise there isno mutual inductance between any of the coils.

G is a superficial earth plate lying on the surface of the earth E, andshown in Fig. 1 as a wire grid or netting.

K is a device which for all rates of change presents a resistanceoperator substantially equal to that of the elevated conductor.

Z in each case is a small inductance coil.

0 in each case is a small condenser.

It is an oscillation detector.

The function of the coil L and condenser C is fully described in myapplication Serial No. 258,763. filed May 4, 1905, and needs no furtherdescription herein.

The functions of the several circuits C1 I1, Cg I2 1'2 and C3 I; R havebeen fully described in my prior Letters Patent, especially LettersPatent Nos. 714:,756, 767,984 and 767,994, and therefore need not bedescribed herein.

The reason for employing the superficial earth plate G is that thecurrents developed in the elevated conductor system and therefore alsoin the earth surrounding the earthed terminal of that system are of suchhigh frequency that they tend to flow only upon the surface of theearth. For this reason the usual specifications for obtaining a goodearth connection which involve burying a conductor of large area so deepin the ground that it shall be in permanently moist earth are notadvantageous in the case of wireless or space telegraphy of the typewhich employs elevated conductors earthed at their lower extremities.

In a properly designed wireless telegraph station of this type,therefore, the conductiv ity of the surface of the earth in theimmediate neighborhood of the base of the oscillator should beartificiallyincreased by asuperficial earth plate composed of sheetmetal or of wire netting, extending radially from the base of I theelevated conductor and covering as large an area about the said base asis available for the purpose and consistent with reasonable economy.

Instead of connecting the lower extremity of the elevated conductor toearth as illustrated in Fig. 1. I maywith advantage in many instancesconnect it as shown in Fig. 2 to an electrical system K which has forall rates of change of the current employed a resistance operator equalto that of the elevated conductor. By either of the means abovedescribed the electrical center of the oscillator considered as a wholeis definitely located. This result, so far as I am aware, has not beenpublished prior to its publication by myself, and also, so far as I amaware, was originally observed by myself.

It will be seen that by means of the present invention, opportunity isafforded to insure definite location of the electrical center of thecomplete oscillator at the point where the receiving or translatingdevice is most conveniently located, to-wit, approximately at the baseof the elevated conductor, and its association therewith at suchlocation insures its operation by the maximum current developed in thecomplete oscillator.

If, as in Fig. 1, a device or devices having a given resistance operatorbe interposed between the elevated conductor per at and the loop circuit0111, then a device or devices having the same resistance operator mustbe similarly interposed between the loop circuit C1 11 and the device K.

The device K may be constructed in a great variety of ways, as in theform shown in Fig. 2 or it may be constructed in the manner of theartificial line so completely set forth by A. Vaschy in AnnalesTelegraphiqiiies,Vol. XVI, pages 517-532, Paris, 1889, and the slowspeed conductor of Prof. Pupin set forth in his papers read before theAmerican Institute of Electrical Engineers in 1899 and 1900. In

this connection it is necessary to point out that there should be alarge number of coils Z and condensers c to a wave length in the deviceK for any frequency likely to be employed, in order that its reactaucemay for all such frequencies closely approximate the reactance of theelevated conductor, or, stated more generally, in order that itsresistance operator may for all the rates of change of the currentsdeveloped in the oscillator closely approximate the resistance operatorof the elevated conductor.

Furthermore it is necessary to point out that the distribution of theinductance and capacity along an elevated conductor is not in generaluniform. For example, in the case of a straight, cylindrical,vertically-elevated conductor per the inductance is relatively smallnear the earth and gradually increases toward the upper end of the wire,as a careful consideration of the writings of Mr. Oliver Heaviside willshow, while the capacity is relatively large near the earth and gradually diminishes toward the upper end of the wire. Because of these factsit is desirable to construct the electrical system K with reference tothe special type of elevated conductor to be employed, to use theadequate number of coils 1 and condensers c, and to slope the values ofthe inductances of the coils and the capacities of the condensers 0approximately after the manner in which they slope in the elevatedconductor.

No claim is made herein to an apparatus whereby the method hereinclaimed may be carried into effect as such apparatus forms the subjectmatter of my application Serial No. 258,762, filed May 4;, 1905, ofwhich the present application is a division.

Having fully described my invention, I claim-- The method of bringingthe electrical center of a complete oscillator to the point at which areceiver is to be associated therewith, which consists in balancing theresistance operator of the elevated conductor by a resistance operatorequal, for all rates of change of the currents developed in theoscillator, to the resistance operator of said elevated conductor.

In testimony whereof I have hereunto subscribed my name this 16th day ofJune, 1905.

JOHN STONE STONE.

Witnesses:

BRAINARD T. JUDKINs, GEORGIA A. Hreems.

